Researchers may use microscopy imaging systems during high-content screenings (HCS) to obtain images of microscopy samples. A sample holder—e.g., a microtiter plate, slide, dish, etc.—may support the microscopy samples during the screening process. Automated microscopy imaging systems may include an objective coupled to an electronic imaging device such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) chip to produce the images of the microscopy samples. The position of the objective relative to the sample holder may be adjusted to bring the microscopy samples into focus on the imaging device.
The microscopy samples may reside at various measurement locations (e.g., wells) on the upper surface of the sample holder. Accordingly, the objective of the microscopy imaging system may be positioned at a focal position relative to the top or the bottom of the sample holder in order to obtain an in focus image of a microscopy sample. Variations in the thickness or curvature of the sample holder, however, may prevent accurate focus over a range of measurement locations. As a result, the focal position of the objective may need to be corrected at each measurement location in order to obtain respective in focus images for all measurement locations. Because high content screenings may image hundreds or thousands of measurement samples, some microscopy imaging systems may be configured to automatically perform focus maintenance at each measurement location.
To increase the efficiency of imaging, multiple imaging devices may be used to image a plurality of wells in parallel (i.e., simultaneously). However, the time required to focus the objective of each of the multiple imaging devices may eliminate any efficiencies that may be gained from parallel imaging. Further, focusing each objective individually may also increase the complexity of the imaging system.
Therefore, improved systems and methods for generating in-focus images of a plurality of measurement locations using imaging devices operating in parallel in a high content screening microscopy-imaging system are needed.